Leather substitute and method of making it.



UNITED STATES PATENT orrroE- REGINALD OLIVER HERZOG, F PRAGUE, AUSTRIA-HUNGARY, AND AUGUST MEIER, OF BERLIN, GERMANY.

LEATHER SUBSTITUTE AND METHOD OF MAKING IT.

No Drawing.

To allwhom it ma concern Be it known t at we, REGINALD OLIVER Hanzoc, a subject of the Emperor of Austria-Hungary, and resident 0 Prague, Bohemia, Austria-Hungary, and AUGUST MEIER, a subject of the German Emperor, and resident of Berlin, Germany, have jointly invented certain new and useful Improvements in' Leather Substitutes and Methods of Making Them, of which the following is a-specification.

Our invention relates to a new type of leather substitute and to the method of makin it.

lextile fabrics have been coated or impregnated with various materials (cellulose compounds in conjunction with drying oils and dye stufi's), thus producing substitutes for leather. These substitutes, however, have properties quite different from those of natural leather.- They lack its strength and its power of resisting the action of water and other agents. The substitute to which the presentinvention relates is free from these defects. It consists of tanned hides or skins composed of microorganisms (bacteria, fungi, etc.) and has properties very similar to those of animal hides.

One method of producing this new type of leather substitute consists in first forming skins by the growth of microorganisms on the surface of a culture medium contained in a suitable vessel, the size (length and breadth) of the skins being determined by the dimensions of the vessel. After an appropriate preliminary treatment, the pur pose of which is to give pliability to the finished article, the skins are tanned in the same manner as natural leather. This preliminary treatment may be carried out with alkalis, for instance by placing the skins in soda lye or in a solution of sodium sulfid; the solutions may be, for example, of about 5% concentration. After removing this preliminary agent (soda lye or sodium sulfid) the tanning process proper is conducted with any suitable tanning agent. As such agents the known vegetable and mineral tanning substances may be used. For example, we may employ oakbark extract, mimosa extract, sumach extract or chestnut extract, all of which are vegetable tanning agents, or chromium salts, alum, iron salts, or cerium salts, all of which are mineral tanning agents. In the case of vegetable extracts, preferably Specification of Letters Patent.

Patented June 1, 1915.

Application filed October 10, 1912. Serial No. 725,033.

solutions of from 5 to 6 B. are used, while in the case of mineral tanning agents, tanning solutions containing at most about 2 to 3% of the tanning agents are used.

The skins composed of microorganisms may be obtained, for instance, by taking a suitable culture medium, such as beer wort, with an addition of alcohol (say, about 9; of one per cent.) and inoculating it with the microorganisms for instance with Bacterium wyZinu-m, Bacterium wylz'noides, Mucor boidz'n. The culture vessels containing the inoculated beer wort are then placed in receptacles in which a temperature favorable to the growth of the microorganisms is maintained, say from about 20 to 35 centigrade. As they grow, the microorganisms will form a layer of uniform thickness covering the surface of the culture medium and of the same size as the culture vessels. The longer the vessels are allowed to stand, the thicker this layer will become. It is true the thickness of the microorganism culture (that is, the top layer just referred to) is from twenty to forty times greater than that of the finished tanned product, but that cultures may attain a thickness of 30 centimeters and over, so that very thick tanned skins may be obtained by our invention.

In order to give the skins greater firmness or density, or to increase their thickness, the microor anisms may be caused to grow upon or ietweensolid substances (textile fabrics, powdered cork) or, instead of this the skins may be produced alone and then put upon woven fabrics or other solid material and subjected to a tanning process together with such material. For the same purpose, a strengthening substance or filling substance, such as resin, soap, etc., may be worked into the skins either before or after tanning. This may be done by subjecting the skins to pressure after they have attained the desired thickness, thus removing the excess of water, and then lacing them ,in a solution of the filling su stance. By

a solution of glue), and subjecting them to any well-known or approved tanning process after they have become coated or impregnated with such albumen bodies. The durability of the final product is increased by this method. It will be evident that in the case of this last describedmethod also, the filling or strengthening substances previously mentioned may be employed, and an addition of fats, oils or glycerin may be made to render these skins also impervious to water and highly pliable.

As regards the woven fabrics used to strengthen the skins, we found that the quality of the final product may be improved greatly by first mercerizing these fabrics so as to increase their density or closeness and to enable them to absorb tanning agents during the tanning process. Good results may also be obtained by placing the bacteria skin '(impregnated with glue or the like, if desired, and also treated, if desired, in the manner set forth above, for the purpose of rendering it pliable or of increasing its strength) on split leather and subjecting the double layer thus formed, to any well known or approved tanning process. A very suitable species of this procedure consists in employing split leather which has been tanned previously. In this case we obtain a product similar to upper leather and capable of being worked into patent leather according to any of the usual methods.

The further steps in the manufacture or finishing of the new leather substitute (such as softening, waterproofing, graining, etc.) may be carried out in a manner similar to that employed in the case of natural leather.

Various modifications may be made without departing from the nature of our invention as set forth in the. appended claims.

We claim 1.. A. leather substitute containing-tanned microorganisms.

2. A leather substitute containing a tanned layer of microorganisms and a strengthening body or substance.

3. A leather substitute containing a tanned layer of microorganisms and a softening agent.

4. A leather substitute containing a tanned layer of microorganisms and an albuminous substance.

5; As a new article of manufacture, a leather substitute comprising split leather and a formation of microorganisms.

6. The process of making a leather sublike layer or formation of microorganisms to grow on a suitable culture medium, compressing said formation, and then tanning it.

8. The process of making a leather substitute, which consists in causing a skin-like layer or formation of microorganisms to grow on a suitable culture medium, treating said formation with an agent adapted to render the final product pliable, and then tanning such formation.

9. The process of making a leather substitute, which consists in causing a skin-like layer or formation of microorganisms to grow on a suitable culture medium, compressing said formation, treating it with an agentadaptedto render the final product pliable, and then tanning the formation.

10. The process of making a leather substitute, which consists in causing a skin-like layer or formation of microorganisms to grow on a suitable culture medium, compressing said formation and then tanning it.

11. The process of making a leather substitute, which consists in causing a skin-like layer or formation of microorganisms to grow on a suitable culture medium. compressing said formation, then subjecting it to a treatment which renders it durable and then tanning it.

12. The process of making a leather substitute, which consists in producing a skinlike formation of microorganisms, combining it with strengthening bodies or substances and then tanning it.

13. The rocess of making a leather substitute, which consists in producing a skinlike formation of microorganisms, treating it with an albuminous solution and then tan ning it.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

REGINALD OLIVER HERZOG. AUGUST MEIER.

Witnesses as to Reginald Oliver Herzog:

VALELITIN ROSENFELD, V. ROBERT STEINER.

Witnesses as to August Meier:

HENRY HASPER, WOLDEMAR HAUPT.

Copies of this patent may be obtained for live cents each, by addressing the Commissioner of Patents, Washington, D. G." 

